Delay arming fuze for projectiles



p 11, 1956 J. M. KING ET AL DELAY ARMING FUZE FOR PROJECTILES 5 Sheets-Sheet 1 Filed June 10. 1953 Tn w. M www WE" n an lmhwa 4 F ow M R93... Y B

Sept. 11, 1956 J. M. KING .ET AL DELAY ARMING FUZE FOR PROJECTILES 3Sheets-Sheet 2 Filed June 10, 1953 W w w $%V p 11, 1956 J. M. KING ET AL2,762 304 DELAY ARMING FUZE FOR PROJECTILES Filed June 10, 1955 3Sheets-Sheet 3 INVENTORS,

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Ix aw .FZTTURNEY5 2,762,304 DELAY ARMING FUZE FOR PROJEC'IIIES John M.King, Dover, James'H. Robinson, Rockaway,

John F. Rowe, Dover, and Wade H. Ewart, Jr., Denville, N. J., assignorsto'the United States of America as represented by the Secretary of theArmy Application June to, 1953, Serial No. 360,852

4 Claims. Cl. 102-811) (Granted under Title 35, U. s. Code 1952 sec.7266) The invention described herein may be manufactured and. used by orfor the Government for governmental purposes without the payment to usof any royalty thereon.

This invention relates to an improved delay arming fuze for projectiles,and more particularly to a fuze for aircraft bombs or missiles.

his a primary object of this invention to provide a fuze for aircraftbombs or missiles which will remain in a safe or disa'rmed conditionduring the initial stage of its flight and which will arm only after themissile-fuze combination have traveled a sufiicient distance so thatdetonation of the fuze will not endanger the crew.

Another object of the invention is the provision of an arming vaneassembly separate and apart from the fuze body assembly but connectedthereto by a rotatable flexible shaft.

A further object of the invention is to provide the fuze with a novelvariable arming means which permits presettingand resetting of the fuze.

Still a further aim of the invention is to provide a fuze in which adetonator of an interrupted explosive train is carried by a rotorassembly which is held in unarmed position by an extension of the armingstem as sembly which also holds the firing pin assembly in unarmedposition. The rotor assembly is arranged so that when moved into armedposition it will not be counterrotated due to shocks arising fromimpact. Other objects and advantages 'of the invention will hereinafterbecome more fully apparent from the following description of thedrawings, which illustrates preferred embodiments thereof and wherein:

Figure 1 is a view in elevation of an aircraft missile provided withseveral'of the fuzes according to the invention.

Figure 2 is a cross sectional view to an enlarged scale of the aircraftmissile taken along the line 2--2 of Figure 1.

Figure 3 is a sectional view taken along the line 3-3 of Figure 2showing the relative positions of the arming vaneassembly and the fuzebody assembly.

Figure 4 is a longitudinal, substantially central sec tionalview of theimproved fuze body, showing the parts in the safe or unarmed position.

Figure 5' is'a cross sectional view taken along the line 5-5 of Figure4.

Figure 6 is a fragmentary sectional view taken substantially along theline-66 of Figure 4.

Figure 7 is a cross sectional view taken along the line 77 of Figure '4.

Figure 8 is a fragmentary sectional View taken sub stantia'lly along theline 8-8 of Figure 4.

' Figure 9 is a cross sectional view taken along the line 9--9 of Figure4.

' Figure 10 isa cross sectional view of the gear lock assembly takenalong the line 10-10 of Figure 4.

Figure 11, is a fragmentary sectional view taken sub stantially alongthe line 11-41 of Figure 4.

7 Figure '12 is a longitudinal sectional view of the arm- 2762304Patented Sept. 11, 1956 ing vane assembly taken substantially along theline 1212 of Figure 3.

Figure 13 is a front elevational view of the arming vane assembly.

Referring more particularly to the drawings, wherein like referencecharacters designate like or corresponding parts throughout the severalviews, there is shown in Figure 1 an aircraft bomb 1, in the conicaltail of which are positioned several fuzes of like structure.

The fuze consists of separate main assemblies, the arming vane assembly2 and the fuze body assembly 3. The two assemblies are positioned sothat the longitudinal axis of the arming vane assembly is substantiallynormal to the longitudinal axis of the fuze body, as is best seen inFigures 2 and 3.

The arming vane assembly 2, best shown in Fig. 12, includes acylindrical housing 4 having reduced externally threaded inner and outerend portions 5 and 6. The inner end portion 5 extends into the innerpart of the tail bomb. A large nut 7 is threaded on the inner endportion of the housing and an apertured cap 8 is threaded on the outerend portion. The cylindrical housing 4 is secured in its outwardlyextending position by the nut 7 which presses a wedge 9 against theinside surface of the bomb tail, and by a second nut 10 threaded on thehousing 4 which presses a washer 11 and a second wedge 12 against theoutside surface of the bomb tail. Positioned in the bore 13 of thecylindrical housing and supported by the shaft bearings 14 and 15 is arigid shaft 16 having inner and outer ends 17 and 18 of reduceddiameter, which extend beyond the large nut 7 and the cap. 8,respectively. On the outer end 18 of the rigid shaft is an arming vane19 having V-shaped blades 20. The inner end 17 of the shaft is threadedto receive a coupling 21, shown in Fig. 3, which secures one end of aflexible metal shaft 22 to the rigid shaft 16. Opposed openings 23 and24 in the cylindrical housing register with a transverse opening 25 inthe shaft 16,'in one position of the shaft, for receiving an arming wire26 (see Figure 3) to hold the shaft against rotatory movement With thearming Wire removed movement of the bomb through the air causes thearming vane to rotate. This rotation is transmitted through the rigidshaft 16 to the flexible shaft 22, and in turn to the gear shaft 30 ofthe reduction gear mechanism of the fuze body assembly 3, as is bestseen in Figure 9.

The reduction gear mechanism is supported by a base member 28 andinclosed by a cup-shaped cover 29. R0- tation of the gear shaft 30causes worm 31 to drive worm gear 32 and worm 33, which in turn mesheswith ring gear 34 to cause that gear to rotate. Ring gear 34 is fixedlymounted on the tubular gear lock housing 35 and causes it to rotate atthe same speed. The gear lock housing is rotatably mounted in the basemember 28 and is formed with a bore 36 having an offset 36. Bore 36forms a bearing for the upper arming stem 37 which is rotatably disposedtherein and which passes through index collar 38 on cover 29. The end ofthe arming stem 37 extending above the cover has a knurled setting knob39 fixed thereto by means of a pin 40. Between the knob 39 and the gearlock housing 35 the arming stem 37 is calibrated in thousands of feet.Immediately below the knob is a keyway 41 in which there is a pivotedcam 42. Adjacent the cam is a spring loaded gear lock detent 43 mountedin the gear lock housing 35 so as to extend into the bore 36 radiallythereof for engagement in the keyway 41, to cause the arming stem andgear lock housing to rotate as a unit. Projecting into the keyway andextending above the knob 39 is a reciprocally movable plunger 44 whichis held in an inoperative position by a volute spring 45 bearing againstthe knob 39 n a aha-lee .cap 16 scann d t the top of the plunger 44. Ashaft lock spring 47 ,is contained in a recess 48 in the lower half ofthe upper arming stem 37, the purp s of which will hereinaflter be setiorth. The lower end of the arming stem is slotted at \49 sons toreceive :the flat sided tongue 50 on the upper .end of the :lower armingstem 51.

The housing for :the .firing pin and explosive train is designatedgenerally as .60. The .upper portion of the housing is :provided with anupwardly opening chamber .61 which :is closed :by a cover .62 secured tothe base member 28 by bolts, .as is best seen in Figure 6. The threaded\portion :of the upper arming stem 37 passes through and is in threadedengagement with the cover I62iandalso with a-cupshaped-plnnger 63 whichis thereby positively held in the safe position in the chamber. Theplunger is provided with an aperture 64 for receiving a downwardlyextending guide pin 65 fixed in the cover. A firing pin '66 is secured'to the center of the plunger 63 and is inline with *the explosive trainwhen the fuze is armed. A helical creep spring-67 surrounds the firingpin and holdsit in a safe position in the absence of the arming stem '37until impact.

Mounted in a cylindrical recess in the side of the housing 60 is acartridge type delay element 70 which also contains a relay charge (notshown). The delay element 70 is locked in position by a spring pressedlatch 71 which engages a peripheral groove 72 in the delay element. Apin73 engages a longitudinal groove 74 in the delay element to properlyseat the element. The two ends 75 and '76 of the latch 71 are of suchlength as 'to prevent seating of the 'fuze body assembly 3 into the bombcavity unless the delay element 70 .is present in the fuze body assemblyand properly positioned therein.

.'Below the delay element 70 the housing 60 is provided with adownwardly opening chamber77 which is closed by a plug 78 containing thetetryl lead 79. Within the chamber 77, as seen in Fig. 7, is a rotor 80of substantially triangular shape having an extremity -81 provided witha pivot ,pin 82 surrounded by a spring 83 which urges the rotor to anarmed position. Another extremity 34 is provided with ashoulderSSadjacent which is a detonator 86. Between the two extremities and inline therewith is ran aperture 87 designed to receive the lower end .88of the-lower arming stem 51, which rotates in unison with the upperarming stem 37 and is mounted in the housing 60 immediately beneath thechamber 61. The portion 88 of the lower arming stem which passes throughthe;rotor andrengages the recessrfi91in'the plng 731s not threaded andpresents a Smooth surface. When thus engaged :the rotor is rheld in theunarmed position with its detonatorout ofzline-with the explosive trainof the delay element'm andttherrelay charge therein. As seen in Fig.75mph! .90 serves as a guide for thetorsionspring 9 1 which presses arotor-lock bar 92 against the rotor. When.' the-rot,or:is=in the armedposition the shoulder is engaged by the motor lock bar tc :OPPOSo anycountermtation of the rotor. A'WinS1 'L9 jS situated in ewal of:theachamber .toreadilydctermine if the rotor isin a-n armediorrunarmedpsiti n- ;To 356i ithe fore ,the spring biased plunger 44 ,on top of thesetting drnob 39 is depressed. When depressed thecus .ofthe plungerstrikes:the pivoted cam 42 which pivots andforees the springloaded,gear'lock'detent 43 out of rtheikfiyway "4.1 to allow thearming stems37 and 51 -.to be rotated independently of'the gear lock housing 5. Qnar volntion frthe arming m ch ng h a travel arming 20f tthe .{fuze .byl=;0 00 .feet. The proper air ravel setting, i o aine by ign g the airtr esired (calibrated .en the upper arming stem) with a preseribedrline.Q rth zindexceollandil.

:l'f'wossafetyic tures.arerp ovided h n-therupncrra ming sterntorpreventza zsettingrofilessrthan5,000 feet. Que feature is the lengthof the cam 42. When a setting of 5,900 test is reached the statuspressed sear lock detest 43 reenters the keyway as ,the cam is of suchlength as to no longer engage the detent. When such an event occurs thearming stem is able to rotate only when the gear lock housing rotatesand (the lower arming stem 51 i l ho ds he q 80 .isan unarme posi i n-Ase n safety feature is the spring shaft lock 47 which enters t s ar l ch us n b re .oits t 3. e t e e ng hfis l ndfi 5,000 feet. This eventcauses the arming stem 37 to become locked to the gear lock housing '35with the result described above.

Once thedesired settingris obtained the bomb 1 is ready for launching.When a bomb containing the fuze is launched, rotation .of the armingvane ZOt-urns the arming vane shaft 16, the flexible shat-t .22 and thereduction gear mechanism to cause rotation of the arming stems 37 and 51which causes them to be unscrewed out of the fuze body. The number ofrevolutions of the vane required to arm the fuze body is determined bythe arming setting. After the required air travel has been accomplished,the arming stems 37 and 51 release simultaneously the spring pressedrotor 80 and the firing pin 66 supported by the creep spring 67.Releasing the rotor allows the detonator 86 to move into alignment withthe explosive charges and 79 and lock in this position. The fuze body isthen armed.

On impact, inertia of the firing pin 66 overcomes the resistance of thecreep spring 67 to ,fire the primer in the cartridge type delay element70, which provides delays of from zero to a .25 second delay. The delayelement r 70 sets the relay charge therein, which in turn functions thedetonator 86 in the rotor 80. The detonator initiates the tetr yl lead'7 9 which detonates a booster charge which in turn detonates the mainbursting charge of the bomb.

We claim:

1. In an air travel del y arm ng fuZe the combination comprising anarming vane assembly normal to and spaced from a fuze body assembly, aflexible shaft driven by .said vane assembly, said fuze body assemblyincluding a reduction gear train driven by said flexible shaft, atubular gear lock housing rotated by said gear train, a two piece partlythreaded arming stern slidably fitting within said tubular gear lockhousing and extendingtherethrough, a threaded bore within said fuze bodyaligned axially with said tubular gear lock housing and threadinglyreceiving said stem along a portion of its length at spaced intervalsthereon, said stern normally rotatably driven by said gear lock housingfor axial movement relative to said fuze body, resetting means todisengage said stem from said gear lock housing for manual rotation ofsaid stem relative to said gear lock housing, a threaded firing pinassembly and a detonator containing rotor held in safe position by saidstem and simultaneously released by said stem to arm said fuze uponrotation of said stern a predetermined number of turns determined bysaid resetting means, a cartridge type delay element positioned withinsaid fuze body in alignment with said firing pin and said rotordetonator in armed position thereof, there being latch means to locksaid cartridge in said position, said latch means preventing seating ofsaid fuze body in a bomb cavity until said delay element is placed insaid fuze body and properly aligned relative to said firing pin androtor detonator, said rotor detonator being of generally triangularshape andpivoted about one extremity thereof, springmeans urging saidrotor into armed position, means to lock said rotor in armed positionand safety stop means for said stern constructed and arranged to preventmanual rotation of said stem towithin a predetermined number of turnsofarmed position thereof.

2. In a fuze body assembly as stated in claim 1, said resetting meanscomprisingan elongated longitudinal keyway formed in the upper portionof said arming stem, a cam pivotally mounted in said keyway, saidcamhaving a generally Wedge like configuration, a cam plungerlongitudinally reciprocal within said keyway, a gear lock detentnormally urged into said keyway, said plunger constructed and arrangedto pivot said cam into engagement with said detent to displace saiddetent from said slot thereby disconnecting said stem and the gear lockhousing to allow manual rotation of said stem with respect to said gearlock housing for a predetermined number of turns only.

3. A fuze body assembly as stated in claim 1 in which said latch meanscomprises a peripheral groove in said cartridge type delay element, atransverse cylindrical bore formed in said fuze body housing normal tosaid cartridge and in alignment with the periphery of said groove whensaid cartridge is properly placed in said housing, a spring loadedpiston slidable in said bore, said piston having an axial rod projectinga predetermined distance from both ends of said piston and of suchlength as to prevent seating of said fuze body assembly into the bombcavity therefore unless said delay element is placed within said fuzebody in proper position.

4. A fuze body assembly as stated in claim 1 in which said safety meanscomprises a resilient member secured to said arming stem, an oflset borein said tubular gear lock housing in juxtaposition With said stem, saidmember abutting the Wall of said ofiset preventing rotation of said stemby said manual means to within a predetermined number of turns of armedposition of said stem.

References Cited in the file of this patent UNITED STATES PATENTS

